Crank Cycle Research Articles

Active control of static pedal force direction decreases maximum isometric force output

Perfect mechanical force effectiveness in cycling would be achieved if the forces applied to the pedal were perpendicular to the crank throughout the full crank cycle. However, empirical observations show that resultant pedal forces display substantial radial components in recreational and even highly-trained elite cyclists. Therefore, we hypothesized that attempting to maximize mechanical effectiveness during the entire downstroke of the pedal cycle must be associated with a penalty that outweighs the benefits of perfect effectiveness. Twenty recreational cyclists performed maximum isometric voluntary contractions at five static crank positions in the downstroke phase of cycling for two testing conditions: (i) a non-constrained (NC) condition, where athletes were asked to produce the maximum force possible on the pedal without consideration of the force direction and (ii) a constrained (C) condition, with the instruction to produce maximal pedal forces perpendicular to the crank. Resultant force and effective force (force perpendicular to the crank in the NC conditions) were compared to the force in the C condition that was, by definition, perpendicular to the crank. Maximum effective force in the NC condition was greater (mean = 50 %, range = 38–69 %) than for the C condition across all crank positions. Applying forces perpendicular to the crank in the downstroke of the pedal cycle resulted in severe reductions in force magnitude, suggesting that coaches and athletes should not attempt to change cycling technique towards perfect force effectiveness.

Criterion validity of neural networks to assess lower limb motion during cycling

ABSTRACT The use of marker-less methods to automatically obtain kinematics of movement is expanding but validity to high-velocity tasks such as cycling with the presence of the bicycle on the field of view is needed when standard video footage is obtained. The purpose of this study was to assess if pre-trained neural networks are valid for calculations of lower limb joint kinematics during cycling. Motion of twenty-six cyclists pedalling on a cycle trainer was captured by a video camera capturing frames from the sagittal plane whilst reflective markers were attached to their lower limb. The marker-tracking method was compared to two established deep learning-based approaches (Microsoft Research Asia-MSRA and OpenPose) to estimate hip, knee and ankle joint angles. Poor to moderate agreement was found for both methods, with OpenPose differing from the criterion by 4–8° for the hip and knee joints. Larger errors were observed for the ankle joint (15–22°) but no significant differences between methods throughout the crank cycle when assessed using Statistical Parametric Mapping were observed for any of the joints. OpenPose presented stronger agreement with marker-tracking (criterion) than the MSRA for the hip and knee joints but resulted in poor agreement for the ankle joint.

PREFERRED SADDLE HEIGHTS EFFECTS ON PEDALLING KINEMATICS AMONG SKILLED AND LESS SKILLED CYCLISTS

The purpose of this study was to compare the movement kinematics between skilled and less skilled cyclists based on their preferred saddle heights. 12 recreational cyclists were recruited for this study, and they were required to perform 10-minute cycling using their own bike (mounted on a bike trainer) which consists of a 4-minute warm-up, and continue with a 6-minute cycle at 90-100 rotations per minute with their preferred saddle height. Reflective markers were placed at the joint involved such as hip, knee, and ankle to assess change in the segment and joint motion parallel to the 90° of the crank cycle (3'o clock) during the study. Additional variables such as cadence and power (watt) were recorded for monitoring purposes. Results showed that there were significant differences (p<0.05) in hip and ankle range of motion during pedalling between skilled and less-skilled recreational cyclists. It can be concluded, significantly better range of motion on the hip and ankle performed by the skilled cyclist may be due to suitable saddle height and it might lead to effectiveness on cycling efficiency.

The effect of vibration on kinematics and muscle activation during cycling

ABSTRACT Vibration has the potential to compromise performance in cycling. This study aimed to investigate the effects of vibration on full-body kinematics and muscle activation time series. Nineteen male amateur cyclists (mass 74.9 ± 5.9 kg, body height 1.82 ± 0.05 m, Vo2max 57 ± 9 ml/kg/min, age 27 ± 7 years) cycled (216 ± 16 W) with (Vib) and without (NoVib) vibration. Full-body kinematics and muscle activation time series were analysed. Vibration did not affect lower extremity joint kinematics significantly. The pelvic rotated with vibration towards the posterior direction (NoVib: 22.2 ± 4.8°, Vib: 23.1 ± 4.7°, p = 0.016, d = 0.20), upper body lean (NoVib: 157.8 ± 3.0°, Vib: 158.9 ± 3.4°, p = 0.001, d = 0.35) and elbow flexion (NoVib: 27.0 ± 8.2°, Vib: 29.4 ± 9.0°, p = 0.010, d = 0.28) increased significantly with vibration. The activation of lower extremity muscles (soleus, gastrocnemius lat., tibialis ant., vastus med., rectus fem., biceps fem.) increased significantly during varying phases of the crank cycle due to vibration. Vibration increased arm and shoulder muscle (triceps brachii, deltoideus pars scapularis) activation significantly over almost the entire crank cycle. The co-contraction of knee and ankle flexors and extensors (vastus med. – gastrocnemius lat., vastus med. – biceps fem., soleus – tibialis ant.) increased significantly with vibration. In conclusion vibrations influence main tasks such as propulsion and upper body stabilization on the bicycle to a different extent. The effect of vibration on the task of propulsion is limited due to unchanged lower body kinematics and only phase-specific increases of muscular activation during the crank cycle. Additional demands on upper body stabilization are indicated by adjusted upper body kinematics and increased muscle activation of the arm and shoulder muscles during major parts of the cranking cycle.

Muscle synergies are modified with improved task performance in skill learning

How do muscle synergies change as motor skills are learned? The purpose of this study was to investigate the relationship between synergy number and skill acquisition, and to examine learning-related changes in synergy structure and activation patterns. We performed muscle synergy analysis using non-negative matrix factorization to identify muscle synergies from activation patterns of ten major leg muscles before and after recreational cyclists learned a novel one-legged pedal force aiming task (Park, Van Emmerik, & Caldwell, 2021). Synergy number was defined as the smallest number of factors from the matrix factorization algorithm that could explain more than the predefined threshold values. Improvements in pedal force direction after practice occurred without a change in the number of muscle synergies (four), suggesting that task constraints (e.g. the need for smooth pedaling motion) in this novel targeting task may limit the CNS to the same number of muscle synergies before and after practice. Improved task performance while continuing to satisfy multiple biomechanical tasks was obtained with changes in structure (muscle weightings) for one synergy, and activation amplitudes without changes in timing or pattern for three synergies. In each crank cycle quadrant, multiple synergies were altered in either structure or activation amplitude, suggesting that the cooperative changes may be essential for improving task performance while producing a smooth pedaling motion. Changes in both synergy structure and activation levels could be muscle coordination strategies in motor skill learning.

Evaluation of an inertial measurement unit-based approach for determining centre-of-mass movement during non-seated cycling

Instantaneous crank power does not equal total joint power if a rider’s centre of mass (CoM) gains and loses mechanical energy. Thus, estimating CoM motion and the associated energy changes can provide valuable information about the mechanics of cycling. To date, an accurate and precise method for tracking CoM motion during outdoor cycling has not been validated. PurposeTo assess the suitability of using data from a single inertial measurement unit (IMU) secured to the lower back of the rider for estimating CoM motion during non-seated cycling by comparing vertical displacement derived from the IMU to that of an attached marker cluster and to a full-body kinematic estimate of vertical CoM displacement. MethodsIMU and motion capture data were collected synchronously for 10 s while participants (n = 7) cycled on an ergometer in a non-seated posture at six combinations of power output and cadence. A limits-of-agreement analysis, corrected for repeated measures, was performed on the range of vertical displacement between the IMU and the two other measures. A total of 303 crank cycles were analysed. ResultsThere was excellent agreement between the vertical displacement derived from the IMU and the attached marker cluster (accuracy = 1.6 mm, precision = 3.5 mm). Vertical displacement derived from the IMU systematically overestimated the kinematic estimate of whole-body CoM—with errors increasing linearly with displacement. ConclusionWe interpret these findings as evidence that a single IMU secured to the lower back can provide a suitable approach for deriving a cyclist’s CoM displacement when they ride out of the saddle, but only if the linearly increasing overestimation is accounted for.

Impact of Power Output on Muscle Activation and 3D Kinematics During an Incremental Test to Exhaustion in Professional Cyclists.

This study aimed to quantify the influence of an increase in power output (PO) on joint kinematics and electromyographic (EMG) activity during an incremental test to exhaustion for a population of professional cyclists. The hip flexion/extension and internal/external rotation as well as knee abduction/adduction ranges of motion were significantly decreased at 100% of the maximal aerobic power (MAP). EMG analysis revealed a significant increase in the root mean square (RMS) for all muscles from 70% of the MAP. Gastrocnemius muscles [lateralis gastrocnemius (GasL) and medialis gastrocnemius (GasM)] were the less affected by the increase of PO. Cross-correlation method showed a significant increase in the lag angle values for VM in the last stage compared to the first stage, meaning that the onset of the activation started earlier during the pedaling cycle. Statistical Parametric Mapping (SPM) demonstrated that from 70% MAP, biceps femoris (BF), tibialis anterior (TA), gluteus maximus (GM), and rectus femoris (RF) yielded larger ranges of the crank cycle on which the level of recruitment was significantly increased. This study revealed specific muscular and kinematic coordination for professional cyclists in response to PO increase.

Influence of muscle fatigue on the pedaling kinetic and kinematics in different cycling protocols: a scoping review

ABSTRACT The aim of this study was to review the literature on the effects of muscle fatigue generated by different cycling protocols, on the kinetics and kinematics of the crank cycle. Twenty-two studies were included in the review. The establishment of the fatigue processes caused an increase in the resulting and effective forces (all tests), together with the pedaling efficiency (incremental and constant tests). In addition, fatigue caused joint changes in the lower limbs (increased range of motion in the ankle and reduced contribution to total torque) in different cycling tests. Therefore, these pedaling strategies may be related to the maintenance of muscle work to postpone the cyclists’ exhaustion.

Influence of saddle height in 3D knee loads commuter cyclists: A statistical parametric mapping analysis

ABSTRACT This study used a statistical parametric mapping method to compare temporal patterns knee joint loads and moments in cyclists pedalling using different saddle heights. Ten recreational cyclists pedalled using three saddle heights (Preferred, High and Low) during a single session. High and Low saddle heights were determined based on dynamically measured knee flexion angles (±10° from their Preferred height). 3D angles for the hip and knee and knee moments and forces were computed using a musculoskeletal model driven by 3D full-body motion and pedal forces. Knee flexion angles presented significant differences between saddle heights for the full crank cycle, without differences for hip adduction/abduction. Patellofemoral force was less for the Preferred compared to the High and Low saddle heights and for the High compared to the Low saddle heights between ~70-160° of the crank cycle. Right tibiofemoral anterior-posterior shear force was reduced for the Preferred compared to the Low saddle heights, without significant effects for the left tibiofemoral joint (p = 0.29–1.00). Large differences in temporal patterns for knee flexion due to changes in saddle height were followed by differences in patellofemoral force mostly when low force magnitudes were being transmitted between the femur and the patella.

Effect of Q-factor manipulation via pedal spacers on lower limb frontal plane kinematics during cycling

Anecdotal evidence suggests that frontal plane kinematics of the lower extremity are an important aspect of bicycle fit, however, frontal plane adjustments are often overlooked during common fitting procedures. The purpose of this study was to manipulate Q-factor width via pedal spacers to determine their influence on frontal plane kinematics of the hip, knee, and ankle during cycling. Twenty-four young healthy recreational cyclists (12 female) completed five minutes of pedaling at their preferred cadence and power output under three stance widths conditions: no spacer, 20 mm spacer, and 30 mm spacer. For each participant, the pedaling cadence and power output were kept identical for all experimental conditions. Lower extremity marker position data were captured at 250 Hz for the last two minutes of each condition. Sixty consecutive crank cycles were analyzed to identify maximum and minimum hip, knee, and ankle angles in the frontal plane. With an increase in Q-factor, hip and knee maximum abduction angles increased and maximum adduction angles decreased. With increase in Q-factor from no spacer to 20 mm spacer condition, hip abduction increased by 0.8o (∆10%; p<0.001) whereas hip abduction decreased by 0.9o (∆23%; p<0.001) and similarly, knee abduction increased by 1.2o (∆60%; p=0.002) whereas knee abduction decreased by 1.1o (∆18%; p=0.003). And with increase in Q-factor from no spacer to 30 mm spacer condition, hip abduction increased by 1.4o (∆18%; p<0.001) and hip adduction decreased by 1.6o (∆40%; p<0.001) and similarly, knee abduction increased by 1.8o (∆86%; p<0.001) and knee adduction decreased by 2.1o (∆35%; p<0.001). Maximum and minimum ankle angles were not affected by the stance width conditions (p>0.05). Pedal spacers are an effective way of manipulating Q-factor and frontal plane kinematics of the hip and knee and could help cyclists experiencing medial or lateral knee pain.

Riders Use Their Body Mass to Amplify Crank Power during Nonseated Ergometer Cycling

To date, neither the CoM movement strategies during nonseated cycling nor the limb mechanics that allow this phenomenon to occur have been quantified. Here we estimate how much power can be contributed by a rider's CoM at each instant during the crank cycle by combining a kinematic and kinetic approach to measure CoM movement and joint powers of 15 participants riding in a nonseated posture at three individualized power outputs (10%, 30%, and 50% of peak maximal power) and two different cadences (70 and 120 rpm). The peak-to-peak amplitude of vertical CoM displacement increased significantly with power output and with decreasing cadence. Accordingly, the greatest peak-to-peak amplitude of CoM displacement (0.06 ± 0.01 m) and change in total mechanical energy (0.54 ± 0.12 J·kg) occurred under the combination of high-power output and low cadence. At the same combination of high-power output and low cadence, we found that the peak rate of CoM energy loss (3.87 ± 0.93 W·kg) was equal to 18% of the peak crank power. Consequently, it appears that for a given power output, changes in CoM energy contribute to peak instantaneous power output at the crank, thus reducing the required muscular contribution. These findings suggest that the rise and fall of a rider's CoM acts as a mechanical amplifier during nonseated cycling, which has important implications for both rider and bicycle performance.

Biomechanics of all-out handcycling exercise: kinetics, kinematics and muscular activity of a 15-s sprint test in able-bodied participants

ABSTRACTThis study aims to quantify the kinematics, kinetics and muscular activity of all-out handcycling exercise and examine their alterations during the course of a 15-s sprint test. Twelve able-bodied competitive triathletes performed a 15-s all-out sprint test in a recumbent racing handcycle that was attached to an ergometer. During the sprint test, tangential crank kinetics, 3D joint kinematics and muscular activity of 10 muscles of the upper extremity and trunk were examined using a power metre, motion capturing and surface electromyography (sEMG), respectively. Parameters were compared between revolution one (R1), revolution two (R2), the average of revolution 3 to 13 (R3) and the average of the remaining revolutions (R4). Shoulder abduction and internal-rotation increased, whereas maximal shoulder retroversion decreased during the sprint. Except for the wrist angles, angular velocity increased for every joint of the upper extremity. Several muscles demonstrated an increase in muscular activation, an earlier onset of muscular activation in crank cycle and an increased range of activation. During the course of a 15-s all-out sprint test in handcycling, the shoulder muscles and the muscles associated to the push phase demonstrate indications for short-duration fatigue. These findings are helpful to prevent injuries and improve performance in all-out handcycling.

Do Surface Slope and Posture Influence Lower Extremity Joint Kinetics during Cycling?

The purpose of this study was to investigate the effects of surface slope and body posture (i.e., seated and standing) on lower extremity joint kinetics during cycling. Fourteen participants cycled at 250 watts power in three cycling conditions: level seated, uphill seated and uphill standing at a 14% slope. A motion analysis system and custom instrumented pedal were used to collect the data of fifteen consecutive cycles of kinematics and pedal reaction force. One crank cycle was equally divided into four phases (90° for each phase). A two-factor repeated measures MANOVA was used to examine the effects of the slope and posture on the selected variables. Results showed that both slope and posture influenced joint moments and mechanical work in the hip, knee and ankle joints (p < 0.05). Specifically, the relative contribution of the knee joint to the total mechanical work increased when the body posture changed from a seated position to a standing position. In conclusion, both surface slope and body posture significantly influenced the lower extremity joint kinetics during cycling. Besides the hip joint, the knee joint also played the role as the power source during uphill standing cycling in the early downstroke phase. Therefore, adopting a standing posture for more power output during uphill cycling is recommended, but not for long periods, in view of the risk of knee injury.

The application of body scanning, numerical simulations and wind tunnel testing for the aerodynamic development of cyclists

The aerodynamic efficiency of an elite cyclist is often evaluated and optimised using either one or a combination of field testing, wind-tunnel testing and numerical simulation. This study focuses on the processes and limitations involved in using a body scan to produce an accurate geometry for input to numerical simulation, with validation through drag comparisons from wind-tunnel tests and vortical wake-flow features reported in previous experimental studies. Transitional Shear Stress Transport Reynolds-Averaged Navier-Stokes simulations based on the scanned geometry were undertaken for a 180 ° half crank cycle at 15 ° increments. The sectional drag force contributions of 23 body subparts are presented, documenting the contribution and variation of each body/cycle component over the cycle. These methods are evaluated and the limitations of the approaches are discussed. The results from the numerical simulation and the wind tunnel measured drag force were very similar, differing by approximately 1%–7% for various crank angles.

Muscular activity patterns in 1-legged vs. 2-legged pedaling

BackgroundOne-legged pedaling is of interest to elite cyclists and clinicians. However, muscular usage in 1-legged vs. 2-legged pedaling is not fully understood. Thus, the study was aimed to examine changes in leg muscle activation patterns between 2-legged and 1-legged pedaling. MethodsFifteen healthy young recreational cyclists performed both 1-legged and 2-legged pedaling trials at about 30 Watt per leg. Surface electromyography electrodes were placed on 10 major muscles of the left leg. Linear envelope electromyography data were integrated to quantify muscle activities for each crank cycle quadrant to evaluate muscle activation changes. ResultsOverall, the prescribed constant power requirements led to reduced downstroke crank torque and extension-related muscle activities (vastus lateralis, vastus medialis, and soleus) in 1-legged pedaling. Flexion-related muscle activities (biceps femoris long head, semitendinosus, lateral gastrocnemius, medial gastrocnemius, tensor fasciae latae, and tibialis anterior) in the upstroke phase increased to compensate for the absence of contralateral leg crank torque. During the upstroke, simultaneous increases were seen in the hamstrings and uni-articular knee extensors, and in the ankle plantarflexors and dorsiflexors. At the top of the crank cycle, greater hip flexor activity stabilized the pelvis. ConclusionThe observed changes in muscle activities are due to a variety of changes in mechanical aspects of the pedaling motion when pedaling with only 1 leg, including altered crank torque patterns without the contralateral leg, reduced pelvis stability, and increased knee and ankle stiffness during the upstroke.

Admittance Control of a Teleoperated Motorized Functional Electrical Stimulation Rehabilitation Cycle

Abstract A bilateral teleoperated rehabilitation cycling system is developed for people with movement impairments due to various neurological disorders. A master hand-cycling device is used by the operator to set the desired position and cadence of a lower-body functional electrical stimulation (FES) controlled and motor assisted recumbent cycle. The master device also uses kinematic haptic feedback to reflect the lower-body cycle’s dynamic response to the operator. To accommodate for the unknown nonlinear dynamics inherent to physical human machine interaction (pHMI), admittance controllers were developed to indirectly track desired interaction torques for both the haptic feedback device and the lower-body cycle. A robust position and cadence controller, which is only active within the regions of the crank cycle where FES produces sufficient torque values, was used to determine the FES intensity. A Lyapunov analysis is used to prove the robust FES controller yields global exponential tracking to the desired position and cadence set by the master device within FES stimulation regions. Outside of the FES regions, the admittance controllers at the hands and legs work in conjunction to produce desired performance. Both admittance controllers were analyzed for the entire crank cycle, and found to be input/output strictly passive and globally exponentially stable in the absence of human effort, despite the uncertain nonlinear dynamics.

Strategies for improving the pedaling technique.

Pedaling technique which can be defined as the way the cyclists pedal, has been mostly studied in lab conditions from pedal force kinetic, joints kinematic, and/or muscular activity patterns because it is considered as a main factor for gross efficiency (GE). Although this method is much controversial, its quality has extensively been evaluated from the index of pedal force effectiveness (IFE), i.e. the ratio between the effective to the total pedal force. Over the last thirty years, preferred pedaling technique has been compared between the experienced cyclists and non-cyclists and also often been manipulated by instructing these subjects to improve their effective force production during the downstroke phase ("pushing"), the upstroke phase ("pulling-up") or around top and bottom dead centers ("circling"). It has been shown that PREF pedaling technique is much repeatable across crank cycles in experienced cyclists than in novice cyclists. PULL involves a significant increase of IFE compared to PREF, mainly attributed to the increase of the muscular work of hip (RF) and knee flexors muscles (BF) during the upstroke. This improvement is larger in non-cyclists than in experienced cyclists but it can be optimized in the latter after a short-term training (2-4 weeks) with pedal force feedback or uncoupled cranks. Despite that PULL enhances a lower muscular recruitment of contralateral knee extensors, GE and cycling performance variables are not significantly increased, probably due to the reversal effect of training with normal cranks and the highly robust pedaling technique of experienced cyclists. The question arises, as to whether or not, changes in pedaling technique can improve cycling efficiency if enough time is given for cyclists to adapt to a new pedaling technique. Further studies should investigate the pedaling techniques in more "ecological" conditions, as there is not probably one but several pedaling techniques that could optimize cycling efficiency according to the pedaling conditions (time-trial, uphill, road, off-road and track cycling), and should also focus on the potential effects of long-term training of PULL pedaling technique on cycling efficiency and cycling performance.

A numerical model for the time-dependent wake of a pedalling cyclist

A method for computing the wake of a pedalling cyclist is detailed and assessed through comparison with experimental studies. The large-scale time-dependent turbulent flow is simulated using the Scale Adaptive Simulation approach based on the Shear Stress Transport Reynolds-averaged Navier–Stokes model. Importantly, the motion of the legs is modelled by joining the model at the hips and knees and imposing solid body rotation and translation to the lower and upper legs. Rapid distortion of the cyclist geometry during pedalling requires frequent interpolation of the flow solution onto new meshes. The impact of numerical errors, that are inherent to this remeshing technique, on the computed aerodynamic drag force is assessed. The dynamic leg simulation was successful in reproducing the oscillation in the drag force experienced by a rider over the pedalling cycle that results from variations in the large-scale wake flow structure. Aerodynamic drag and streamwise vorticity fields obtained for both static and dynamic leg simulations are compared with similar experimental results across the crank cycle. The new technique presented here for simulating pedalling leg cycling flows offers one pathway for improving the assessment of cycling aerodynamic performance compared to using isolated static leg simulations alone, a practice common in optimising the aerodynamics of cyclists through computational fluid dynamics.

Motorized and Functional Electrical Stimulation Induced Cycling via Switched Repetitive Learning Control

Cycling induced by functional electrical stimulation (FES) coupled with motorized assistance is a promising rehabilitative strategy. A switching controller that activates lower limb muscles alongside an electric motor based on the crank angle is developed to facilitate cycling. Due to the periodic nature of cadence tracking in cycling, a repetitive learning controller (RLC) is developed to track a desired cadence trajectory with a known period. The RLC is developed for an uncertain, nonlinear cycle-rider system with autonomous state-dependent switching. Electrical stimulation switches across multiple lower limb muscle groups based on the torque effectiveness throughout the crank cycle. The electric motor provides assistance when the muscle groups yield low torque production. A Lyapunov-based stability analysis that invokes a recently developed LaSalle–Yoshizawa corollary for nonsmooth systems is used to guarantee asymptotic tracking. The developed controller was tested during FES-cycling experiments in five able-bodied individuals and three participants with neurological conditions. The added value of the RLC in cadence tracking is illustrated by comparing the results of two trials with and without the learning feedforward term. The results indicate that the RLC yields a lower mean root-mean-squared cadence tracking error.

Distributed Repetitive Learning Control for Cooperative Cadence Tracking in Functional Electrical Stimulation Cycling.

Closed-loop control of functional electrical stimulation coupled with motorized assistance to induce cycling is a rehabilitative strategy that can improve the mobility of people with neurological conditions (NCs). However, robust control methods, which are currently pervasive in the cycling literature, have limited effectiveness due to the use of high stimulation intensity leading to accelerated fatigue during cycling protocols. This paper examines the design of a distributed repetitive learning controller (RLC) that commands an independent learning feedforward term to each of the six stimulated lower-limb muscle groups and an electric motor during the tracking of a periodic cadence trajectory. The switched controller activates lower limb muscles during kinematic efficient regions of the crank cycle and provides motorized assistance only when most needed (i.e., during the portions of the crank cycle where muscles evoke a low torque output). The controller exploits the periodicity of the desired cadence trajectory to learn from previous control inputs for each muscle group and electric motor. A Lyapunov-based stability analysis guarantees asymptotic tracking via an invariance-like corollary for nonsmooth systems. The switched distributed RLC was evaluated in experiments with seven able-bodied individuals and five participants with NCs. A mean root-mean-squared cadence error of 3.58 ± 0.43 revolutions per minute (RPM) (0.07 ± 7.35% average error) and 4.26 ± 0.84 RPM (0.1 ± 8.99% average error) was obtained for the healthy and neurologically impaired populations, respectively.